Ch. 1-4 test Flashcards
Methods of organizing, summarizing, and presenting data in an informative way.
Descriptive Statistics
Methods used to estimate a property of a population on the basis of a sample
Inferential Statistics
The entire set of individuals or objects of interest or the measurements obtained from all individuals or objects of interest
Population
A portion, or part of the population
Sample
What’s the difference between quantitative and qualitative
Qualitative is non-numeric and Quantitative is numeric
Variables that can only assume certain values and there are gaps between the values
Discrete variables
Variables that can assume any value within a specific range.
Continuous variables
Describe ordinal measurements
Ranked based on defined attribute or qualitative variable
Describe nominal measurements
Can only be classified and counted. Examples are labels or names
Describe interval measurements
The interval between values has to have meaning such as a known scale. Has no defined 0
Describe ratio measurements
Based on a scale of known measurements and has a meaningful zero
A grouping of qualitative data into mutually exclusive and collectively exhaustive classes showing number of observations in each class
Frequency table
A graph that shows qualitative classes on the horizontal axis and the class frequency on the vertical axis
Bar chart
A chart that shows the proportion or percentage that each class represents of the total number of frequencies
Pie Chart
A grouping of quantitative data into mutually exclusive and collectively exhaustive classes showing the number of observations in each class
Frequency distribution
Using a percentage to describe frequency distribution
Relative Frequency distribution
A graph in which the classes are marked on the horizontal axis and the class frequencies on the vertical axis. Like a bar chart, but bars or adjacent with no space.
Histogram
Shows the shape of a distribution and is similar to a histogram. uses a line to connect segments mid points
Frequency Polygon
Cumulative Frequency Distribution
Arithmetic mean
The midpoint of the values after they have been ordered from the minimum to the maximum values
median
Class of distribution with the highest frequency
mode
A convenient way to compute the arithmetic mean when there are several observations of the same value
Weighted mean
Used to find percentage change over time.
Geometric mean
Dispersion the measures The maximum - the minimum value
Range
The arithmetic mean of the square deviations form the mean
Variance
The square root of the variance
Standard Deviation
For any set of observations, the proportion of the values that lie within k standard deviations of the mean is at least 1-1/ksquared
Chebyshev’s theorem
States that for a bell shaped frequency distribution, 68% of the observations will lie within plus or minus 1 SD, 95% within 2, and 99.7 within 3.
Empirical rule
Summarizes the distribution of one variable by stacking dots at points on a number line that shows the values of the variable.
Dot plot
Values of an ordered data set that divide the data into four intervals
Quartiles
Values of an ordered data set that divide the data into 10 equal parts
Deciles
Values of an ordered data set that divide the data into 100 intervals
Percentiles
A graphic display that shows the general shape of a variables distribution based on 5 descriptive statistics, minimum, maximum, 1st & 3rd quartiles, and median.
Box Plot
graphical technique used to show the relationship between two variables measured with interval or ratios scales
Scatter Diagram
A table used to classify sample observations according to two identifiable characteristics
Contingency table
